Evaluation of the integrity and function of the nervous system in critically ill patients who are comatose or who have some alteration of mental status is difficult to carry out in an ongoing fashion. During FY 85-87 a neurological monitoring system was developed to acquire, analyze and display scalp-recorded neuroelectric signals (EEG and evoked potentials). This system has been integrated into a collaborative project with the Department of Neurology and Neurosurgery at The Cleveland Clinic Foundation and placed into service in the Neurosurgical Intensive Care Unit at that location. Programs to carry out dynamic state space analysis of EEG, time varying filtering of evoked potentials, and pharmacokinetic evaluation have been developed.